Ответ:
1. If a shop assistant gave me too much change, I would give it back.
2. If I had a bank account, I would pay all my bills by direct debit.
3. He wouldn't pay his bus fare if nobody asked him for it.
4. If I earned a lot of money, I would give more to charity.
5. I ate out more if it wouldn't be so expensive.
6. Would you leave a tip in a restaurant if the service was poor?